Method for making polyetherimides and products produced thereby

ABSTRACT

A method is provided for making polyetherimides involving the reaction of aromatic bis(ether anhydride)s and organic diamines in the presence of a phenolic solvent. The resulting polyetherimide-phenolic solvent mixture can be employed as a wire coating enamel.

i United States Patent 1191 Takekoshi et al.

[ Nov. 4, 1975 METHOD FOR MAKING POLYETHERIMIDES AND PRODUCTS PRODUCED THEREBY Inventors: Tohru Takekoshi, Scotia, N.Y.;

John E. Kochanowski, Pittsfield, Mass.

General Electric Company, Schenectady; NY.

Filed: June 22, 1973 Appl. No.: 372,769

Assignee:

US. Cl. 260/326 R; 260/326 S; 260/326 A;

117/31 Int. Cl. C07D 209/34 Field of Search 260/326 S, 326 R, 326 A References Cited UNITED STATES PATENTS 11/1971 Dickert, Jr 260/326 S Primary Examiner-Elbert L. Roberts Attorney, Agent, or Firm-William A. Teoli; Joseph T. Cohen; Jerome C. Squillaro 57 ABSTRACT A method isprovided for making polyetherimides involving the reaction of aromatic bis(ether anhydride)s and organic diamines in the presence of a phenolic solvent. The resulting polyetherimide-phenolic solvent mixture can be employed as a wire coating enamel.

6 Claims, No Drawings The present invention relates to polyetherimides which can be made by effecting reaction between an aromatic bis(ether anhydride) and an organic diamine in a phenolic solvent.

Prior to the present invention, polyimides derived from the reaction of organic dianhydrides and organic diamines were generally therrnoset and made by producing an intermediate polyamide acid. As shown by Edwards US. Pat. No. 3,179,614, the polyamide acid is preferably obtained by reacting the organic dianhydride and the organic diamine with a dipolar aprotic solvent at temperatures of 50C or below. One of the reasons for careful temperature control is that premature formation of water of reaction leads to depolymerization of polymer. In addition, imidization occurs as soon as the temperature exceeds optimum limits which can decrease polymer solubility and solution shelf life.

As shown by our copending application Ser. No. 319,371, filed Dec. 29, 1972, and assigned to the same assignee as the present invention, certain polyimides, such as polyetherimides can be made by effecting reaction between an aromatic bis(ether anhydride) and an reaction between substantially equal molar amounts of aromatic bis(ether anhydride)s of the formula,

II II C I a c 0 0 R 0 a O and organic diamine of the formula,

in the presence of a phenolic solvent produces a solution which remains homogeneous when the mixture is allowed to cool to room temperature. There is obtained a solution of polyetherimide in the phenolic solvent which can be used directly as a wire coating enamel or for applying polyetherimide onto various substrates. If desired, the polyetherimide can be recovered by effecting its separation from the phenolic solvent mixture with a non-solvent for polyetherimide, such as methanol.

As shown in formula I, R is a member selected from the class consisting of (a) the following divalent organic radicals:

( arb organic diamine in the presence of an inert organic solvent such as orthodichlorobenzene at temperatures of 55 at least 130C. Although polyetherimides can be made at elevated temperatures, often a plural phase mixture of inert organic solvent and polyetherimide results, particularly when the reaction mixture is allowed to cool to room temperature. In addition, the water of reaction 60 and the immiscible ortho-dichlorobenzene can cause foaming and complicate recovery of the polyetherimide. As a result, an added separation step is required before the polyetherimide can be used if the high temperature method is employed. 5

The present invention is based on the discovery that and (b) divalent organic radicals of the general formula where X is a member selected from the class consisting of divalent radicals of the formulas and -S, where m is O or 1, y is a whole number from 1 to 5, and R is a divalent organo radical. selected. from the class consisting of (a) aromatic hydrocarbon radicals having from 6-20 carbon atoms and halogenated derivatives thereof, (b) alkylene radicals, C 8 alkylene terminated polydiorganosiloxane cycloalkylene radicals having from 2-20 carbon atoms, and (c) divalent radicals included by the formula, 5

and x is a whole number from 1 to inclusive, and m is aspreyiously defined.

There is provided by the present invention, a method for making a polyetherimide, which comprises,

(1) effecting reaction between aromatic bis(ether anhydride) of formula I and organic diamine of formula II, in the presence of a phenolic solvent at temperatures between about 100C to 250C while effecting the removal of water of reaction,

(2) separating said polyetherimide from the resulting mixture of l). 1

where Q is a member selected from the class consisting There is also provided by the present invention, a 2

wire coating enamel having a viscosity of from 200 to 2000 centipoises at 25C, comprising a solution of polyetherimide in a phenolic solvent, where the polyetherimide consists essentially of from 2 to 500, and preferably from 10 to 200 of chemically combined units of the formula,

where R and R are as previously defined. As used above, and hereinafter, the term phenolic solvent includes phenol and mixtures of 0-, pand m-cresols known as cresylic acid and mixtures of cresylic with phenol. In addition" phenolic solvent also includes ethylphenols, isopropylphenols, ter-butylphenols, xylenols, chlorophenols, dichlorophenols, phenylphenols, etc. The wire coating enamels of the present invention can have from 1 to 40 parts of polyetherimide, per 100 parts of phenolic solvent, 7 I

Included by the aromatic bis(ether anhydride)s of formula I are compounds having the formulas,

O O C C 4 2 I o IQ I (V) 0 2 1 l Q Q where R is I and Q is selected from Dianhydrides included by formula IV are, for example,

2,2-bis[4-(2,3-dicarboxyphenoxy)phenyl]propane dianhydride; 4,4'-bis(2,3dicarboxyphenoxy)diphenyl ether dianhydride;

V l,3-bis( 2,3-dicarboxyphenoxy)benzene dianhydride;

' by Koton, M. M.; ,Florinski, F. S.; Bessonov, M.- I.;

Rudakov, A. P. (Institute of Heteroorganic Compounds, Academy of Sciences, USSR) USSR 257,010, Nov, 11, 1 9 6. 9, Appl. May 3, 1967. In addition dianhydridesflshown M.M. Koton, F.S. Florinski, Zh Org. Khin Some of the aromatic bis(ether anhydride)s of formula l are shown in copending application of Darrell Heath and Joseph Wirth, Ser. No. 281,749, filed Aug. 18, 1972, and assigned to the same assignee as the pres ent invention. These dianhydrides can be prepared from the hydrolysis, followed by dehydration, of the reaction product of a nitro-substituted phenyl dinitrile with a metal salt of a dihydric phenol compound in the presence of a dipolar aprotic solvent. For example, a benzenoid compound of the formula,

N NOZA@:CCN

where the N0 group can be positioned anywhere in the benzene ring, can be reacted in dimethylformamide with an alkali metal salt of a dihydric phenol of the general formula,

Alk-O-R -o-Alk where R is a divalent aromatic radical and Alk is an alkali metal ion. Various well known procedures can be used to convert the resulting tetranitriles to the corresponding tetra-acids and dianhydrides.

Included by the alkali metal salts of the above described dihydric phenols are sodium and potassium salts of the following dihydric phenols:

2,2-bis(2-hydroxyphenyl)propane;

2,4'-dihydroxydiphenylmethane;

bis(2-hydroxyphenyl)methane;

2,2-bis(4-hydroxyphenyl)propane hereinafter identified as bisphenol-A or BPA;

l 1 -bis( 4-hydroxyphenyl )ethane;

l,1-bis(4-hydroxyphenyl)propane;

2,2-bis( 4-hydroxyphenyl )pentane;

3,3-bis(4-hydroxyphenyl)pentane;

4,4-dihydroxybiphenyl;

4,4 '-dihydroxy-3 ,3 -tetramethylbiphenyl;

2,4'-dihydroxybenzophenone;

4,4'-dihydroxydiphenyl sulfone; 2,4'-dihydroxydiphenyl sulfone; 4,4-dihydroxydiphenyl sulfoxide; 4,4'-dihydroxydiphenyl sulfide; 3,4-dihydroxydiphenylmethane; 4,4'-dihydroxybenzophenone; 4,4'-dihydroxydiphenyl ether;

hydroquinone;

resorcinol, etc.

Included by the organic diamines of formula II, are,

for example,

m-phenylenediamine; p-phenylenediamine; 4,4'-diaminodiphenylpropane; 4,4-diaminodiphenylmethane; benzidine; 4,4-diaminodiphenyl sulfide; 4,4'-diaminodiphenyl sulfone; 4,4-diaminodiphenyl ether; 1 ,S-diaminonaphthalene; 3 ,3 -dimethylbenzidine; 3 ,3 '-dimethoxybenzidine; 2,4-bis( B-amino-t-butyl )toluene; bis(p-,B-amino-t-butylphenyl)ether; 4,4-diaminobenzophenone; bis(p-B-methyl-o-aminopentyl)benzene; l ,3-diamino-4-isopropylbenzene; l ,2-bis( 3-aminopropoxy )ethane; m-xylylenediamine; p-xylylenediamine; 2,4-diaminotoluene; 2,6-diaminotoluene; bis(4-aminocyclohexyl)methane; 3-methylheptamethylenediamine; 4,4-dimethylheptamethylenediamine;

2,1 l-dodecanediamine; 2,Z-dimethylpropylenediamine; octamethylenediamine; 3-methoxyhexamethylenediamine; 2,S-dimethylhexamethylenediamine; 2,5-dimethylheptamethylenediamine; 3-methylheptamethylenediamine; S-methylnonamethylenediamine;

1 ,4-cyclohexanediamine;

l ,12-octadecanediamine;

bis(3-aminopropyl)sulfide;

N-methyl-bis(3-aminopropyl)amine;

hexamethylenediamine;

heptamethylenediamine;

nonamethylenediamine;

decamethylenediamine;

bis( 3-amin opropyl )tetrametlhyldisiloxane;

bis(4-aminobutyl)tetramethyldisiloxane; etc.

The polyetherimide reaction products can be reinforced with conventional silica fillers, for example, perlite, fume silica, etc., carbon whiskers, glass fibers, etc. at proportions of from 10 to 60 parts of filler, per parts of polyetherimide.

In the practice of the method of invention, reaction is effected between the aromatic bis(ether anhydride)s and the organic diamines in the presence of a phenolic solvent.

The order of addition of either reactants is not critical. It is preferred to effect the reaction of the dianhydride and the organic diamine in an inert atmosphere such as nitrogen. Experience has shown that sufficient phenolic solvent should be utilized to provide a solids content in the range of about 10% to 50%.

Reaction can be effected at a temperature of from 100C to 250C, and preferably C to 200C.

In order to provide optimum contact between the aromatic bis(ether anhydride) and the organic diamine, the reaction mixture can be agitated such as by stirring, etc. Substantially equal moles of reactants has been found to provide for optimum molecular weight of polymer; however, there can be employed from 0.5 to 2 moles and preferably 0.9 to 1.1 moles of aromatic bis(ether anhydride) per mole of organic diamines for effective results. It has been found that the polyetherimide can have from about 5 to 500 repeating aromatic bis(ether anhydride)-organic diamine reaction product units and preferably 10 to 200. Terminal amino and phthalic acid or phthalic anhydride end groups can be present.

Reaction time of the bis(ether anhydride) of formula I and the organic diamine of formula II can vary from 0.5 to 20 hours depending upon such factors as the temperature employed, degree of stirring, nature of the reactants, etc.

During the course of polymer formation, water of reaction is continuously removed. The course of the reaction can be readily determined by the actual amount of water generated, as a percentage of the theoretical. In particular instances, a mixed solvent system can be employed consisting of a phenolic solvent and a low boiling solvent which forms an azeotropic mixture with water. The low boiling solvents such as cyclohexane benzene, toluene, chlorobenzene, etc. can be used.

At the termination of the reaction, recovery of polye therimide can be effected by pouring the polymer solution upon cooling into a precipitant such as methanol, etc., followed by washing, filtering, etc.

In order that those skilled in the art will be able to practice the invention, the following examples are given by way of illustration and not by way of limitation. All parts are by weight. EXAMPLE 2 EXAMPLE 1 A mixture of 2011 parts of l,4-bis(2,3-dicarbXy- A mixture of 3 parts of 2,2-bis[4-(2,3-dicarboxyphenoxy)benzene dianhydride and -9 pa t o phenoxy)phenyl]propane dianhydride and 1.152 parts diaminodiphenylmethane and about 30 Parts of trichloof 4,4 -diaminodiphenyl ether, about 40 parts of phenol rObenZene was h at d to flux r n h u During and 10 parts of toluene were heated to reflux for 4% the time the miXtUfe was heated, Water Was COIIIiIII-I- hours. During this period water was continuously azeoously removed by azeotropic distillation. Polymer 10 troped from the mixture. The mixture was then allowed formed during t period of reaction ma n d ns luto cool to room temperature. There was obtained a s0- ble even though the temperature of the mixture was as lution of polyetherimide consisting essentially of rehigh as 230C. peating units of the formula,

0 O 8 k N/ 9* The above reaction mixture was then allowed to cool having a viscosity of about 1100 centipoises at C. to room temperature and about 5 parts of meta-cresol 25 The identity of the product was confirmed by its IR and 2 parts of toluene were added. The mixture was respectrum and method of preparation. The polyetheriheated to reflux. An additional amount of water was mide was a light yellow fibrous polymer which was rapidly formed and the polymer formed during the remade at a yield of about 98.6% after a titer of the soluaction completely dissolved. The mixture was allowed tion was precipitated in methanol. to cool to room temperature and a viscous polymer so- The above polyetherimide solution is employed as a lution was obtained. Based on method of preparation wire coating enamel as described in Example 1 to prothe product was a solution of a polyetherimide. A titer duce a coated aluminum conductor having valuable of the solution was poured into methanol to effect the characteristics. precipitation of product. There was obtained a light yellow fibrous polyetherimide at a yield of about EXAMPLE 3 92.5%. Anal. Calc. for C i-1 N 0 C, 74.46; H, 3.57; A mixture of 3.000 parts of 2,2-bis[4-(3,4-dicarboxy- N, 4.96. Found: C, 74.1; H, 3.8; N, 5.3. The polyetheriphenoxy)phenyl]propane dianhydride, 1.143 parts of mide consisted essentially of repeating units of the for- 4,4-diaminodiphenylmethane, about parts phenol mula, and about 10 parts toluene 10 ml) was heated to reflux II II C C II 0 0 0 o The identity of the polyetherimide was confirmed by its at 150 to 154C for 1.25 hours during which time the IR-spectrum. water formed was removed as an azeotrope. Upon A portion of the above described polyetherimide socooling, the reaction mixture was poured into methanol lution having a viscosity of about 900 centipoises is ernto yield fibrous precipitate of the polymer. The yield ployed to treat a copper wire. A copper wire is passed was 3.67 part (93.3%). A transparent, tough film was through the polyetherimide solution and then baked for b i d b casting f hl f l ti Th IR minutes at 350C. There was obtained an insulated Spectrum f th fil h d that th polymer consists copper conductor having valuable characteristics. n i ll f repeating units f h f l E @t@ C EXAM L 4 A copper conductor is dipped into a portion of the A mixture of 3000 parts Of22 biS[ 4 (z,3 dicarboxy above phenolic solution of polyetherimide. The wire is then allowed to air dry at ambient temperature to prof phenoxymhenynpropane dlanhydnde 1 143 parts duce a valuable insulated conductor.

4,4-diaminodiphenylmethane, about parts of toluene and about 35 parts of technical grade cresylic acid was heated at 170C for 2 hours, during which time the EX MP 7 water formed was removed azeotropically. The reaction mixture was poured to precipitate fibrous polymer. A i t f 6232 parts f 4 4' bi (2 3 di b The yield Of t p ly Was 3 g The phenoxy)dipheny1 ether dianhydride, 1.374 parts of trinsic viscosity in DMF was 0.47 dl/g. Based on meta-phenylenediamine, parts of meta-cresol and 7 method of preparation the polymer consisted of repeatparts of toluene was heated at 140C for 20 minutes ing units of the formula, during which time water formed was removed by azeo- 0 0 II H C c N/ N CH CH C n I I u 0 o o o I CH EXAMPLE 5 tropic distillation. The toluene was distilled off and the reaction mixture was heated at 160C for 10 minutes.

A mixture of 3.000 parts of 2,2-bis[4-(3,4-dicarboxy- The resulting viscous solution was cooled and diluted phenoxy)phenyl]propane dianhydride, 1.143 part of with about 25 parts of m-cresol. The viscosity of the so- 4,4-diaminodiphenylmethane, about 10 parts of O lution was 960 centistokes at 25C. A titer of the soluene and about parts of technical cresylic acid was tion was poured into methanol to precipitate the white heated at 160C for 2 hours. The water formed was refibrous polymer. The intrinsic viscosity of the polymer moved azeotropically. The polymer was precipitated in 35 was 0.25 and glass transition temperature was 205C. methanol, the yield was g (9 Based on Anal. Calc. for C H N O C, 72.08; H, 3.20; N, 4.95. method of preparation and its infrared spectrum, the Found: C, 71.9; H, 3.5; N, 5.4. Based on the method polymer consisted essentially of repeating units of the or preparation and the above analysis the polymer formula, consists essentially of repeating units of the formula,

0 0 II II C C CH -N N CH II II 0 CH 0 EXAMPLE 6 EXAMPLE 8 A mixture of 3.000 parts of 2,2-bis[4-(3,4-dicarboxy- A mixture of 1.98 parts of 4,4'-diaminodiphenylphenoxy)phenyl]propane, 1.1 15 parts of 4,4- methane, 2.60 parts of 2,2-bis[4-( 2,3-dicarboxydiaminodiphenyl ether, about 10 parts of toluene and phenoxy)-phenyl]propane dianhydride, 2.60 parts of about 50 parts of ortho-chlorophenol was heated to re- 2,2-bis[4-( 3,4-dicarboxyphenoxy)phenyl]propane difiux at 150C for 4 hours. The water formed during the anhydride, 40 parts of cresylic acid, and 10 Parts Of reaction was removed by use of a modified Dean-Stark uene was heated to reflux for 2 hours during which time trap filled with 4A molecular sieves. A titer of the polythe water formed was continuously removed azeotropimer was precipitated in methanol, the yield was 3.32 Cally. Toluene was removed by distillation and the re- (89.1%). The intrinsic viscosity in DMF was 0.40 dl/g. action mixture was cooled. The resulting viscous, ho-

very many polyetherimides which can be made in ac-.

cordance with, the invention, as well as wire' coating compositions made thereby; it should be understood that the present invention is broadly directed to polyetherimides made by effecting reaction between aromatic bis(ether anhydride) of formula I and organic diamine of formula II in the presence of a phenolic solvent.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. A method for making a polyetherimide, which comprises,

1. effecting reaction between aromatic bis( ether anhydride) of the formula,

and organic diamine of the fonnula,

H2NRNH2, in the presence of a phenolic solvent at temperatures between about 100C to 250C while effecting the removal of water of reaction,

2. separating said polyetherimide from the resulting mixture of 1), where R is selected from the class consisting of a. the following divalent organic radicals,

CH CH3 CH3 eager Bi: c11

CH Br Br CH3 -O-, and -S-,- where m is Oor 1, y is a whole number from 1 to 5, and R is a divalent organo radical selected from the classconsistingof (a) aromatic hydrocarbon radicals having from 6-20 carbon atoms and halogenated derivatives thereof, (b) alkylene radicals, C(21) alkylene terminated polydior ganosiloxane cycloalkylene radicals having from 2-20 carbon atoms, and (c) divalent radicals included by the formula,

where Q is a member selected from the class consisting of and x is a whole number from 1 to 5 inclusive, and m is as previously defined.

. 2. A method in accordance with claim 1 where the aromatic bis(ether anhydride) is O I II C C 0 \C 40 ii 0 R 8 where R is and (b) divalent organic radicals of the general formula and Q is selected from where X is a member selected from the class consisting of divalent radicals of the formulas 3. A method in accordance with claim 1 where the aromatic bis(ether anhydride) is 

1. A METHOD FOR MAKING A POLYETHERIMIDE WHICH COMPRISES,
 1. EFFECTING REACTION BETWEEN AROMATIC BIS(ETHER ANHYDRIDE) OF THE FORMULA
 2. separating said polyetherimide from the resulting mixture of (1), where R is selected from the class consisting of a. the following divalent organic radicals,
 2. A method in accordance with claim 1 where the aromatic bis(ether anhydride) is
 2. SEPARATING SAID POLETHERIMIDE FROM THE RESULTING MIXTURE OF (1) WHERE R IS SELECTED FROM THE CLASS CONSISTING OF A. THE FOLLOWING DIVALENT ORGANIC RADICALS, -1,3-PHENYLENE-, -1,4-PHENYLENE-, AND (B) DIVALENT ORGANIC RADICALS OF THE GENERAL FORMULA
 3. A method in accordance with claim 1 where the aromatic bis(ether anhydride) is
 4. A method in accordance with claim 1 where water of reaction is separated by the use of azeotroping organic solvent.
 5. A method in accordance with claim 1 where the organic diamine is methylene dianiline.
 6. A method in accordance with claim 1 where the organic diamine is oxydianiline. 